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Jan. 29, 1929.

R. w. JOHNSON SAFETY DEVICE FOR GAS WATER HEATER'S Filed Aug. 7, 1926 E 2 4 z 4 2 H z 2 m.. 1 M q I] n. ar/55f. KL M m H w a w Patented Jan. 29,1929.-

UNITED STATES 1,700,315 PATENT OFFICE.

ROY W. JOHNSON, OF MILWAUKEE, WISCONSIN, ABSIGNOR TO THE TIME-0 81A! COR-.-

PANYOF umwauxnn, WISCONSIN, A conrona'rion or WISCONSIN.

sax-my nnvrcn'ron ens warm; mamas.

Application filed August 7, 1926. semi No. 127,875.

This invention relates to improvements in safety devices of the type more particularly adapted for use in connection with water heaters. 4

One of the objects of the present invention is to provide an improved safety device for attachment to the storage tank of a water heater and including latching mechanism connected to the gas supply valve for the heater and operable upon failure of .the householder to close the gas valve or upon failure of the latter to close 'for other reasons to uncock or move to releasing positionwhen a predetermined amount of water in the tank has been heated and permit closing of the gas valve under the action of the usual weight connected thereto and urging the same into closed position at all times.

Another object is to provide an improved safety device of the character referred to wherein the latching mechanism is adjustable in such wise as to vary the amount of water heated in the tank before the device becomes eifective to permit closing of the gas valve.

Another object is to rovide an improve safety device of. the c aracter referred to which may be readily applied to water heaters such as are now in extensive use and without the necessity of changing the construction thereof, which is simple and positive in operation, and which may be manufactured at a relatively small cost.

Other objects and advantages will hereinafter appear.

For the purpose of illustratin the invention, one embodiment thereof is rown in the drawings, in which 7 Figure 1 is an elevational view, showing a common type of water heater with the improved safety device applied thereto;

Fig. 2 is an enlarged central vertical sectional view through the improved safety device;

Fig. 3 is a sectional view, taken on the line 33 in Fig. 2;

Fig. 4 is a sectional view, taken on the line sake of clearness.

, The water heater, designated generally by the reference numeral 10, is of well-known construction and is provided with the burner 11 and the gas supply valve 12 normally urged to closed position by the weight 13 depending from the lever 14 to which is connected the controlling element or cable 15 trained over the pulleys 16 and 17 and running upwardly into the room above for actuation by the householder to raise lever 14 and permit opening of valve 12 and operation of the burner or to permit lowering pf lever 14 under the action of weight 13 to close valve 12, a constantly burning pilot 18 being provided to ignite the gas upon open-- ing of valve 12. The pulley 16 is sup orted by a suitable bracket 18" secured, as own, from the pipe 19 extending upwardly from the upper end of the heating coil 20, while the pulley 17 is connected to the improved safety device in the manner hereinafter explained, the pulleys being arranged as shown to provide a hitch in cab e 15 wherebya relatively slight bodily movement of pulley 17 toward pulley 16 is suflicientto let out on the cable enough to permit downward valved closing movement of lever 14 under the action of weight 13.

The improved safety device comprises the elongated heat-responsive base or member 21 provided on one side thereof with longitudinally extending recess 22 and substantially U-shaped in cross-section, as shown in Fig. 3, the member being secured or held against the storage tank 23 in heat-conductive relation with respect thereto by-the metal band 24 clinched aroundthe'tank and extending through registering openin s in o posite edges of the member at sulistantially the center thereof. 1

. Latch mechanism, designated generally in Fig. 1 by the reference numeral 26, is mounted on-base 21 and includes the means or lever 27 pivotally connected at one end thereof by means of the pin 28 to the upper end of member 21 and provided with the arm 29' to which pulley 17 is connected, as shown. When the lever or element 27 is in osition coextensive with member 21, pulley 1 is held in position as shown in Fig. 1 to place the necessary hitch in the controlllng element or cable 15 to lift lever 14 to valve-opening position against the action of weight 13. j For the purpose of holding lever 27. in this position, a latch or hook 28 is supported at the lower end of member 21 and normally held in engaging relation with a dog 29 pivotally connected to the lower free end of lever 27 by the pin 30 and provided with a shoulder engageable with the lever to limit pivotal movement of the dog in a clockwise direction while permitting pivotal movement of the dog in the opposite irectionfor the purpose hereinafter explained.

An adjusting bolt 32 is threaded into the portion 33 formed integrally-with member 21 and depending from the lower end thereof, and a lug or part 34 threaded into the bolt or part 32 as shown, latch 28 being pivotally connected intermediate its ends tothe upper end of part 34 by the pin 35. The pitch of the threads of part 32 is substantially different than that of the threads of part 34, the part 32 being provided with a substantially less number of threads to the inch than the part 34. It will, therefore, be seen that upon rotary movement of part 32 in the direc tion of the arrow in Fig. 2, the latter will move inwardly and part 34 will be threaded further into part 32, part 24 and latch 28 carried thereby being moved bodily upwardly an amount corresponding to the difference between the pitch of the threads of parts 32.and 34. The latch 28 is provided with the upstanding lug 36 having its upper end disposed in a recess 37 cut in member 21 whereby latch 28 and the supporting part 34 therefor are held against rotary movement with part 32. The latch 28 is urged at all times out of engaging or holding relation with lever 27 by the spring 38 disposed in the recess 39 in portion 33 and compressed between latch 28 and the pin 40 having a press fit in portion 33 and extending across recess 39, as shown.

A relatively non-expansible elongated element or rod 41, which may be made of porcelain or other suitable material, is disposed in recess 22 coextensive with member 21, the upper end of this element fitting into the upper endof member 21 and seating against the plug 42 screwed into the latter, the lower end of element 41 extending downwardly and loosely through and beyond the'lower end of member 21 and engagin an upstanding lug 43 with which latch 28 1s provided.

When the device is set, as shown in Fig. 2, the lower end of the'relatively non-expansible element 41 engages lug 43 of latch 28 to revent movement of the latter under the action of spring 38 out of engaging orholding relation with dog 29. In the event that the householder neglects to drop cable 15, or the cable is prevented from dropping for any reason after the water in the tank 23 has been heated to the point desired, member 21 will expand due to the heat conducted thereto from the tank, while element 41 will retain substantially its normal length'whereby the position of pin 35 is lowered and latch 28 permitted to tilt clockwise under the action of spring 38 out of holding relation with dog 29 and lever 27 permitted to swing outwardly 14 to drop under the action of weight 13 to from member 21 to permit substantial movement of pulley 17 to the right, whereby the cable 15 is let out sufficiently to permit lever valve-closing position. It will thus be seen being dependent upon the position of pin 35 which may be adjusted as explained above by the adjusting means comprising the parts 32 and 34 threaded one within the other.

By providing member 21 with the recess 22, the heat radiating from tank 23 is stored up in the recess and member 21 thus made more sensitive to rise intemperature of the wall of the tank, the recess 22also receiving the element 41 whereby the latterisenclosed and protected by member 21.

l/Vhen the latching mechanism 26' has been released, in the manner explained. it may be reset by merely swinging lever 27 back to the left in position coextensive with member 21,

the dog 29 tilting in a counter-clockwise direction upon engagement thereof with the hook end of latch 28 and riding over the latter and snapping into latching engagement therewith under the action of the spring 44 which may be secured to member 21 by the screw 45. The spring 45 holds dog 29 in a given angular relation with respect to lever 27 with its shoulder 31 engaging the latter whereby the amount of expansion of member 21 effective to release the latch mechanism is dependent solely on the position of adjustment of latch The amount of expansion of member 21 effective to cause movement of latch 28 out of holding relation with dog 29 may be varied by turning the bolt or part 32 on which may be placed designating marks, as more clearly shown in Fig. 6, arranged to align with an indicating mark 46 on portion 33 to indicate to the householder the approximate temperature to which the water in tank 23 will be heated before the safety device functions to permit closing of the gas supply valve 12 under the action of weight 13. I

The member or base 21 may be provided with lugs 47 spaced and arranged as shown to receive and guide lever 27 upon movement thereof into latching relation with the latch 28 to insure that the hook end of the latch becomes properly engaged with dog 29.

It will be noted that the point of engagement of the lower end of rod 41 with lug 43 is a relatively less distance from the pivot or fulcrum 35 than the point of engagement of dog 29 with the hook end of latch 28, whereby downward movement of the pin 35 upon expansion member 21 causes a substantially greater movement of the hook end of the latch to disengage the same from dog 29. By reason of this construction, therefore, movement of latch 28 out of holding or latching relation with dog 29 is augmented for a given amount ,of expansion of member 21, and the device.

thereby rendered very responsive to rise in temperature of tank. 23 to automatically permit closing of the gas supply valve 12 in the manner explained.

One embodiment of the invention has been shown and described, but of course various changes may be made, such as in the size, shape and arrangement of the parts without departing from the spirit of the invention or the scope of the claims.

The invention claimed is:

1. The combination with apparatus of the character described including a water heater, a controlling element therefor, a storage tank, and means connected to said element and opera'ble when in a given position to place the latter in position to cause operationof said heater, of a relatively fixed heat-responsive member associated with said tank in heatconductive relation with respect thereto, a latch normally engaged with said meansfor holding the same in said position, said latch being carried by said member for bodily movement therewith out of holding relation with said means upon expansion of said member a predetermined amount, and means carried by said member and eooperable upon expansion thereof with the same and with said latch to augment said movement of said latch out of with one of its ends engaging said end of said member, and a latch normally engaged with the free end of said lever to hold the latter in said position, said latch being carried by the other end of said member for pivotal movement with respect thereto out of holding relation with said lever to permit movement of the latter out of said position, said non-expansible part engaging said latch and cooperable therewith and with said member upon expansion of the latter to cause said pivotal movement of said latch.

3. The combination with apparatus of the character described including a water heater, a controlling element therefor, and a storage tank, of an elongated heat-respon-- sive member secured to said tank, a lever pivotally connected at one end to one end of said member for movement into position coextensive therewith and connected to said heater to cause operation of the latter when in said position,'a relatively non-expansible elongated part arranged coextensive with said member with one of its ends engaging said end of said member, a latch normally engaged with the free end of said lever to hold the latter in said position, said latch being carried by the other end of said member for pivotal movement with respect thereto out of holding relation with said lever to permit movement of the. latter out of said position, said non-expansible part engaging said latch and co-operable therewith and with said member upon expansion of the latter tocause said pivotal movement of said latch, and means operable to effect bodily adjusting movement of said latch with respect tesaid member in such wise that the amount of expansion of the latter etl'ective'to cause movement of said latch out of holding relation with said lever may be varied.

4. A device of the character described comprising an elongated heat-responsive member, a lever pivotally connected at one end to one end of said member for movement into position substantially coextensive with the latter, a relatively non-expansible elongated part arranged coextensive with said member with one of its ends seating against said end ofsaid member, and a latch normally engaged with the free end of said lever for holding the latter in said position and carried by said member at the other end thereof for pivotal movement with respect thereto out of holding relation with said lever, said part coac-ting with said latch and cooperating with said member upon expansion of the latter to impart said pivotal movement to said latch.

5. A device of the character described comprising an elongated heat-responsive member provided on one side thereof with a recess,

latch mechanism carried by said member, a

relatively nonexpansible element disposed in said recess and cooperable with said mechanism and said member upon expansion of the latter to effect releasing movement of said mechanism, and means for holding said device in heat-conductive relation with respect to a tank with the recessed side of said member adjacent the latter.

'6. A device of the character described comprising an elongated heat-responsive member provided on one side thereof with a recess, latch mechanism carried by said member, a relatively nonexpansihle elongated element disposed in said recess and arranged coextensive with said member, said element coacting with said mechanism and said member upon expansion of the latter to effect releasing movement of said mechanism, and means for tion with respect to a tank with the recessed side of said member adjacent the latter.

7. The combination with a device of the character described including a heat-responsive member and latch mechanism operated thereby upon expansion thereof, of means operablc with said mechanism for adjusting the same in such wise as to vary the amount of expansion of said member etlective to operate said mechanism, said means comprising a plurality of parts threaded one within the other, the outermost part being threaded in said member and provided with threads hav ing a different pitch than that of the threads of the other of said parts.

8. Ina device of the character described, a base of heat-responsive material, latch mechanism mounted on said base and comprising a lever pivotally connected at one end to said base, a dog mounted on the free end of said lever for pivotal movement and provided with a shoulder engageable with the latter to limit such movement of said dog in one direction, a hook normally engaged with said dog to hold said lever against pivotal movement away from said base, said. dog engaging said hook upon pivotal movement of said lever into latching relation with the latter and moving in the opposite direction upon such engagement, and means operable upon expansion of said base to impart movement to said hook out of engaging relation with said dog.

9. In a device of the character described, a base of heat-responsive material, a lever connected at one end thereof to said base for pivotal movement away from the latter, a latch normally engaged with said lever for holding the same against such movement, a

member carried by said base for axial adjusting-movement with respect thereto, said latch being carried by said member for adjusting movement therewith, and. means op erable upon expansion of said base to impart movement to said latch out of holding relation with said lever, said latch being arranged in such wise as to permit variation of the amount of expansion of said base effective to impart said last-named movement to said latch upon said adjusting movement of the latter.

10. In a water heating apparatus, a heater, a valve controlling the How of fuel to the heater, a storage tank operatively associated with the heater, distant control cable means for the valve, a lever controlled de- ,vice for maintaining an operative tension in said distant control cable means, a heat responsive element having a high co-efiiclent of expansion and mounted directly on and subject to the heat of the tank, a latch tulcrumed on the heat responsive element and engageable with the lever to hold said lever controlled device in position to maintain an operative tension on the distant control cable means, said latch being automatically released by the heat responsive element when the Water in the tank is heated above a predetermined point, and means for shifting the fulcrum of the latch to vary the point at which the latch is disengaged from the lever.

a valve controlling the flow of fuel to the. heater, a storage tank operatlvely associated with the heater, distant control cable means for the valve, a tensioning device for maintaining an operative tension in said distant control cable means, a heat responsive elementhaving' a high co-efiicient of expansion mounted directly on and subject to the heat of the tank, a latch fulcrumed on the heat responsive element and cooperable with said tensioning device, a non-expansible element cooperable with the latch for causing the same to engage and hold the tensioning device in such position as to maintain'an operative tension in the distant control cable means until the water in the tank is heated above a predetermined point, and means forbiasing the latch to disengage said device when the Water in the tank is heated above a predetermined point and the heat responsive element expands to a predetermined degree.

12. In a water heating apparatus, a heater, a valve controlling the flow of fuel to the heater, a storage tank operatively associated with the heater, distant control cable means for the valve, a tensioning device for maintaining an operative tension in said distant control cable means, a heat responsive element having a high co-efiicient of expansion mounted directly on and subject to the heat of the tank, a latch mounted on the heat responsive element, said tensioning device having a controlling part also mounted on the heat responsive element and cooperable with the latch whereby the latch holds the tensioning device in such position as to maintain an operative tension in the distant control cable means until the water in the tank is heated above a predetermined point Wl1618 upon the expansion of the heat responsive element acts to disengage the latch and the controlling part of the tensioning device.

In witness whereof, I hereto aflix my signature.

not w. JOHNSON.

11. lln'a water heating apparatus, a heater, 

